The present invention relates generally to a power source for supplying power to a circuit and, in particular, to a voltage regulator that uses a multi-sense feedback scheme to improve voltage (IR) drops.
For efficient and desirable operation of electrical circuits, a constant voltage supply must be maintained at all points of time. Power supplies are used for providing a constant voltage to such electrical circuits. These power supplies or regulated power sources, receive as input an unregulated voltage, which may vary with time due to operational parameters, and provide an output voltage, which is fixed in magnitude and therefore called a regulated voltage.
During the operation of an electrical circuit, the load attached to the regulated power source draws current from the regulated power source. The load can be a resistive load and its source can be the impedance of the power supply network. In certain cases, a voltage (IR) drop occurs resulting in a lower voltage at the load than at the regulated power source's output terminals. This voltage drop is a result of the current flowing through the impedance of the power supply network. As a result, the electrical circuit receives a supply voltage that is less than the desired voltage. Further, this voltage may be fluctuating. Such an unregulated supply voltage may lead to improper functioning of the electrical circuit. In particular, the IR drop may lead to problems such as reduced noise margin, static power consumption, and logic failures.
Conventionally, a regulated power source senses the voltage at its output terminals and regulates the voltage at this point. Systems prone to distribution voltage drops in the power supply network are provided with sense pins, which monitor the voltage at a load point. The monitoring of the voltage at the load point enables the regulated power source to adjust its output so that the voltage across the load is regulated.
Conventional systems provide for single point sensing, which works well when a single load element is placed across the regulated power source's output. In case of multiple loads, each load has to be connected across a single point for single point load sensing to work correctly. Also, the conventional systems do not necessarily sense the maximum voltage drop in the power distribution network before providing feedback from the regulated power sources to counter the voltage drop.
Accordingly, it is an object of the present invention to provide a voltage regulator having a multipoint feedback scheme to compensate for voltage drops.